Drawbar assembly and method for integrated structure

ABSTRACT

A drawbar assembly for transporting a manufactured building comprises an A-frame. The A-frame further comprises two arm beams, each arm beam having first and second ends. The first ends of the arm beams are connected together to form the apex of the A-frame, and the second ends of the arm beams are disposed so that the two arm beams form an acute angle. There are at least first and second cross beams, the first cross beam being connected to the second ends of the arm beams; the second cross beam being connected across the arm beams between the apex of the A-frame and the first cross beam. There are two perimeter beams for supporting a structure; and, the two perimeter beams are removably connected to the cross beams of the A-frame.

TECHNICAL FIELD

This patent application relates to the field of factory-built housing, including manufactured housing such as mobile homes; in particular, to apparatus that allows a manufactured structure, such as a garage, to be integrated into a building and transported to a building site.

BACKGROUND

Homes and similar residential dwelling units have traditionally been constructed on-site. Moreover, residential dwelling units have typically been constructed on an individual unit basis, even in the case of construction projects wherein the individual homes are largely identical. These factors, plus delays caused by weather and unavailability of materials, have combined to dramatically increase the cost of homes constructed in the conventional manner.

By contrast, factory-built homes are constructed in factories. Automation, standardization, and other mass production techniques, have kept the costs of manufacturing factory-built homes relatively low. Thus, when compared on a per-square foot basis, homes constructed by conventional techniques can cost up to five times as much as factory-built homes.

Building homes under the roof of a factory combines the best features of traditional construction and factory-built housing to provide residential dwelling units that are economical to purchase and yet afford many of the amenities that have heretofore been unavailable at reasonable prices. Each home is constructed from one or more modules that are entirely constructed at a factory using mass production techniques. The completed modules are transported from the factory to the home site on either a permanent chassis (required for manufactured homes), or on a removable chassis or carrier for factory-built homes. At the site the modules are installed on a foundation. Walks and driveways, patios, decks, pools, hot tubs, and other amenities usually found only in expensive custom homes are then added to complete the construction of the factory-built home.

In the manufactured-home industry, it is still common to build an automobile garage for the home on the site to which the home is delivered, rather than incorporate the garage into the factory-built home itself; in the United States this is partly because of limitations set forth by the Federal Manufactured Home Construction and Safety Standards. A garage must have a foundation floor to support automobiles, and this floor cannot be incorporated into the main building unit floor built of main beams and floor joists. The practice of building a garage on site has the disadvantage that the efficiencies of factory construction are partly lost when a garage (or any addition) to the home must be built on-site by traditional methods.

The prior art shows attempts to solve this problem by transporting a factory-built garage to the installation site, placing it on the garage slab and integrating it into the manufactured house. Prior-art solutions have required the transported garage to have flooring joists and other bracing installed for structural integrity during transport, and these joists must then be removed when the garage is set over the floor slab. Also, prior-art solutions have required time-consuming removal of the I-beams used to support the walls of the garage during transport.

What is needed is a way to integrate a manufactured garage with a manufactured home, transport it to a home site, and place it on the garage floor slab without requiring removal of floor bracing or I-beams, while also allowing the drawbar used for transport to be easily removed and used again.

The reader should note that the improvements described below are not limited to garages, but are applicable to the transport and installation of any structure to be integrated with a manufactured building.

SUMMARY

A drawbar assembly for transporting a manufactured building comprises an A-frame. The A-frame further comprises two arm beams, each arm beam having first and second ends. The first ends of the arm beams are connected together to form the apex of the A-frame, and the second ends of the arm beams are disposed so that the two arm beams form an acute angle. There are at least first and second cross beams, the first cross beam being connected to the second ends of the arm beams; the second cross beam being connected across the arm beams between the apex of the A-frame and the first cross beam. There are two perimeter beams for supporting a structure; and, the two perimeter beams are removably connected to the cross beams of the A-frame.

In another embodiment, a chassis for supporting a structure comprises two perimeter beams, and rim joists attached to and running the length of the perimeter beams; each rim joist has first and second ends. A front header joist is connected across the first ends of the rim joists. A header beam is connected across the second ends of the perimeter beams; and, a drawbar assembly is connected to the perimeter beams.

We also disclose a method of manufacturing a chassis for transporting a structure, the method comprising the following steps: Connecting perimeter beams to a drawbar assembly; the perimeter beams having first and second ends; attaching rim joists to the perimeter beams; the rim joists having first and second ends; attaching a header joist between the first ends of the rim joists; attaching a header beam between the second ends of the perimeter beams; attaching the header beam to the main-unit beams; and, connecting cable cross-bracing between the perimeter beams.

DRAWINGS

FIG. 1 is a perspective view of the drawbar assembly of the preferred embodiment.

FIG. 2 shows the perimeter beams for the garage connected to a header for integration with the manufactured building.

FIG. 3 shows the stage of assembly where the perimeter beams and header and rim joists are placed over the drawbar assembly of the preferred embodiment.

FIG. 4 shows the cross-bracing arrangement to be used with the drawbar assembly of the preferred embodiment.

FIG. 5 shows the assembled garage and drawbar of the preferred embodiment in place over a prepared slab.

FIG. 6 shows the garage in place over the slab after removal of the drawbar apparatus.

DESCRIPTION

FIG. 1A shows the drawbar assembly (100) for the preferred embodiment. The drawbar assembly (100) comprises an A-frame (110) made preferably from steel I-beams. The A-frame has two arm beams (115), and at least two cross-beams (120), also preferably steel I-beams (three cross-beams are shown in FIG. 1A). A ten-inch I-beam is suitable for the A-frame (110), and an eight-inch I-beam is suitable for the cross-beams (120). The apex of the A-frame has a coupler (130) for attachment to a towing vehicle. The ends of the cross-beams (120) have brackets (140) with holes for removable attachment to the perimeter beams (150) of the chassis (235) for the garage or other structure to be assembled. The brackets (140) are shown more clearly in FIG. 1B.

FIGS. 2-4 show construction of a typical chassis (235) on the drawbar assembly (100). Perimeter I-beams (150) of suitable strength for the application are connected to main-unit beams (160) and header beams (170) at the end of the chassis (235). The term “main unit” refers to the house or other building to which the integrated garage is to be connected. The perimeter (150), main-unit (160), and header beams (170) are preferably welded together.

FIG. 3A shows the framing of the garage upon the chassis (235) constructed from the drawbar assembly (100), the perimeter beams (150) and the main-unit (160) and header beams (170). The perimeter beams (150) are connected to the cross-beams (120) of the A-frame (110), preferably removably, by means of bolts through the brackets (140). Rim joists (190) are attached to the perimeter beams (150), preferably using screws (155), as shown in detail FIG. 3B. The rim joists in the preferred embodiment (190) are doubled, and the doubled joists are extended into the floor framing of the main unit on each side of the chassis (235) for at least four feet. Floor joists (180) for the floor of the main unit are added at the portion of the assembly where it is connected to the main unit. At the front, or opening of the garage, a header joist (200) is connected to the a cross-beam (120) on the A-frame (110) and also to the rim joists (190). Preferably, the header joist includes a full-length joist (210) faced with shorter joists (220); the latter defining the opening of the garage. Of course, in applications where the drawbar assembly (100) is used to transport a structure other than a garage, the header joists (200) may both be continuous or interrupted in some other appropriate way.

Although the garage here used as an example is shown constructed of wood, the drawbar assembly and method are equally applicable to buildings of metal-beam construction.

FIG. 4 shows the placement of removable cable cross-bracing (230) between the sides and corners of the rectangle defined by the perimeter beams (150) and the joists (180, 200) just described. The cable cross-bracing is preferred for most applications to provide structural rigidity needed during transportation. Typical cable cross-bracing (230) would be ⅜-inch steel cable tightened by turnbuckles (not shown). After installation of the cable cross-bracing (230), the main unit with integrated garage is built on the chassis (235) by means conventional in the factory-built housing industry.

After construction of the main unit and the integrated garage, the drawbar assembly (100) bearing the completed building (or one section of the building, if it is divided into multiple sections for transport) can be connected to a vehicle (not shown) at the coupler (130) and transported to the building site. Not shown are a conventional axle and wheels connected under the main beams of the main unit, so that the entire structure can be towed by a vehicle.

FIG. 5 shows a manufactured garage on the drawbar assembly (100), having been transported to the house site. For clarity, the completed roof structure of both the main unit and garage extension are not shown. FIG. 4 shows the end wall (240) and the side wall (250) of the garage, and also sheathing (260) installed on the walls (240, 250). The draw-bar assembly (100) and the garage carried by it are placed over a pre-poured slab foundation (270). A hitch jack (not shown) or other means conventional in home installation is adjusted to keep the complete unit level. At this stage, perimeter walls (280) are placed under the perimeter beams (150) and support walls are placed under the header joists (200); both are attached to the slab (270) by anchor bolts (290). The perimeter walls (280) may be attached to the perimeter beams (150) by screws as shown in FIG. 3B. The drawbar assembly can now be unbolted from the perimeter beam (150) where it was attached by brackets (140) and withdrawn from the now-installed garage.

The drawbar assembly is withdrawn in three steps. First, the cable bracing (230) is removed; second, the A-frame (110) is disconnected from the cross beams (120) and removed. Finally, the cross beams (120) are disconnected from the perimeter beams (150) and removed.

FIG. 6 shows the garage in place over the slab (270) with the drawbar assembly (100) withdrawn and the full-length header joist (210) cut away to create an opening (300) for the garage door.

Since those skilled in the art can modify the specific embodiments described above, we intend that the claims be interpreted to cover such modifications and equivalents. 

1. A drawbar assembly for transporting a manufactured building; the drawbar assembly comprising: an A-frame; the A-frame comprising: two arm beams, each arm beam having first and second ends; the first ends of the arm beams connected together to form the apex of the A-frame; the second ends of the arm beams disposed so that the two arm beams form an acute angle; at least first and second cross beams, the first cross beam connected to the second ends of the arm beams; the second cross beam connected across the arm beams between the apex of the A-frame and the first cross beam; two perimeter beams for supporting a structure; and, the two perimeter beams removably connected to the cross beams of the A-frame.
 2. The drawbar assembly of claim 1, further comprising a coupler attached to the apex of the A-frame.
 3. The drawbar assembly of claim 1, further comprising a third cross beam, the third cross beam connected across the arm beams between the first and second cross beams.
 4. The drawbar assembly of claim 1, where the cross beams are removably connected to the A-frame.
 5. A chassis for supporting a structure, the chassis comprising: two perimeter beams, rim joists attached to and running the length of the perimeter beams; each rim joist having first and second ends; a front header joist; the front header joist connected across the first ends of the rim joists; a header beam; the header beam connected across the second ends of the perimeter beams; and, a drawbar assembly; the drawbar assembly connected to the perimeter beams.
 6. The chassis of claim 5, further including main-unit beams for connection to a pre-existing structure; the main unit beams connected to the header beam.
 7. The chassis of claim 5, further including cable cross-bracing connected between the perimeter beams.
 8. The chassis of claim 5, where the drawbar assembly is removably connected to the perimeter beams;
 9. The chassis of claim 5, where the front header joist is faced with shorter joists; the shorter joists defining the opening of a garage door.
 10. The chassis of claim 5, where the drawbar assembly further comprises: an A-frame; the A-frame comprising: two arm beams, each arm beam having first and second ends; the first ends of the arm beams connected together to form the apex of the A-frame; the second ends of the arm beams disposed so that the two arm beams form an acute angle; at least first and second cross beams, the first cross beam connected to the second ends of the arm beams; the second cross beam connected across the arm beams between the apex of the A-frame and the first cross beam; and, the two perimeter beams connected to the cross beams of the A-frame.
 11. The chassis of claim 10, further comprising a coupler attached to the apex of the A-frame.
 12. The chassis of claim 10, further comprising a third cross beam, the third cross beam connected across the arm beams between the first and second cross beams.
 13. The chassis of claim 10, where the cross beams are removably connected to the perimeter beams.
 14. A method of manufacturing a chassis for transporting a structure, the method comprising the steps of: connecting perimeter beams to a drawbar assembly; the perimeter beams having first and second ends; attaching rim joists to the perimeter beams; the rim joists having first and second ends; attaching a header joist between the first ends of the rim joists; attaching a header beam between the second ends of the perimeter beams; attaching the header beam to the main-unit beams; and, connecting cable cross-bracing between the perimeter beams.
 15. The method of claim 14, further comprising the step of attaching floor joists over the main-unit beams.
 16. The method of claim 14, where the step of attaching a header joist between the first ends of the rim joists further comprises: attaching a single full-width joist between the first ends of the rim joists; and, attaching two less than full-width joists to the full-width header joist, so as to define the opening of a garage door.
 17. A method of integrating a manufactured structure with a pre-existing structure; the manufactured structure constructed on a chassis; the chassis having perimeter beams, a header joist, cable cross-bracing, and a drawbar assembly supporting the perimeter beams and the header joist; the drawbar assembly having an A-frame and cross beams: locating the manufactured structure over a pre-positioned foundation slab; installing perimeter walls under the perimeter beams; installing support walls under the header joist; removing the cable cross-bracing; removing the A-frame from the cross beams; and, removing the cross beams from the perimeter beams.
 18. The method of claim 17, further including bolting the perimeter walls and support walls to the foundation slab.
 19. The method of claim 17, further including the steps of: providing one full-width header joist and two shorter joists attached to the full-width header joist; and, and cutting away the full-width header joist between the two shorter joists to define a door.
 20. The method of claim 17, further including the step of installing sheathing over the footers, support walls and perimeter beams. 